Here's [http://forums.somethingawful.com/showthread.php?threadid=3394882] a very good guide to pet nutrition. You should definitely use it.
As other people have said, definitely get it from a shelter rather than a store.
Also make sure you play with you potential cat before adopting it. A lot of people don't seem to do this, which is how they end up with a cat with a shitty personality. If the cat seems friendly, happy, and playful rather than violent, panicky, or listless, then it will most likely remain that way for the rest of its life. Getting a kitten or a cat basically amounts to the same thing, as long as in either case you spend some time with it first and as long as the kitten wasn't taken from its mother at too young an age (under 2 months). Don't worry about not being able to train a kitten to use a litter box. Just show it where the box is and place it inside from time to time if necessary, and the rest is instinct (unless it has mental issues).
Don't forget to check around your apartment for potential hazards (poisonous houseplants, electrical wiring, etc.) and find a way to keep it away from the cat.
As for litter, in our house we do this:
1. Get a litter box and fill it with kitty litter (obviously).
2. Get a large plastic storage bin with a lid that both the litter box and the cat can fit comfortably inside, and put the litter box in it.
3. Cut a hole in the side of the bin for the cat to walk in through.
4. Set it in a shallow plastic basin to catch any stray litter.
5. Turn the hole to face the wall, but make sure the cat still has room to get in and out of it.
This eliminates virtually all litter box smells.
Oh, and ALWAYS make sure it's neutered or spayed. Always.